The present invention relates to the preparation of alkaline divalent silver (Ag(II)) bactericidal compositions. Said compositions are useful for a variety of applications ranging from water treatment to compounding surgical soaps. More particularly, this invention is concerned with changing bactericidally active Ag(II) complexes in acid solutions to stable alkaline compositions without destroying Ag(II) ion capabilities of the resulting composition, for it is well known that Ag(II) ions are favored in acid solutions in contradistinction to alkaline solutions. Said Ag(II) acid complexes comprise the subject matter of the inventor's U.S. Pat. No. 5,017,295 entitled Divalent Silver Bactericides for Water Treatment. Said bactericides failed to act in their sanitizing capacity when subjected to elevated pH. Furthermore, there was a need to be able to apply these compositions to a variety of conditions where an alkaline pH is essential, such as the aforementioned surgical soaps, disinfectant laundry detergents, dairy and food processing plant cleaners, etc. It was found that a special form of material called puffed borax was capable of converting said Ag(II) complexes into viable alkaline bactericides.